drivers/video/fbdev/core/fbcmap.c

   1 /*
   2  *  linux/drivers/video/fbcmap.c -- Colormap handling for frame buffer devices
   3  *
   4  *      Created 15 Jun 1997 by Geert Uytterhoeven
   5  *
   6  *      2001 - Documented with DocBook
   7  *      - Brad Douglas <brad@neruo.com>
   8  *
   9  *  This file is subject to the terms and conditions of the GNU General Public
  10  *  License.  See the file COPYING in the main directory of this archive for
  11  *  more details.
  12  */
  13
  14 #include <linux/string.h>
  15 #include <linux/module.h>
  16 #include <linux/fb.h>
  17 #include <linux/slab.h>
  18 #include <linux/uaccess.h>
  19
  20 static u16 red2[] __read_mostly = {
  21     0x0000, 0xaaaa
  22 };
  23 static u16 green2[] __read_mostly = {
  24     0x0000, 0xaaaa
  25 };
  26 static u16 blue2[] __read_mostly = {
  27     0x0000, 0xaaaa
  28 };
  29
  30 static u16 red4[] __read_mostly = {
  31     0x0000, 0xaaaa, 0x5555, 0xffff
  32 };
  33 static u16 green4[] __read_mostly = {
  34     0x0000, 0xaaaa, 0x5555, 0xffff
  35 };
  36 static u16 blue4[] __read_mostly = {
  37     0x0000, 0xaaaa, 0x5555, 0xffff
  38 };
  39
  40 static u16 red8[] __read_mostly = {
  41     0x0000, 0x0000, 0x0000, 0x0000, 0xaaaa, 0xaaaa, 0xaaaa, 0xaaaa
  42 };
  43 static u16 green8[] __read_mostly = {
  44     0x0000, 0x0000, 0xaaaa, 0xaaaa, 0x0000, 0x0000, 0x5555, 0xaaaa
  45 };
  46 static u16 blue8[] __read_mostly = {
  47     0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa
  48 };
  49
  50 static u16 red16[] __read_mostly = {
  51     0x0000, 0x0000, 0x0000, 0x0000, 0xaaaa, 0xaaaa, 0xaaaa, 0xaaaa,
  52     0x5555, 0x5555, 0x5555, 0x5555, 0xffff, 0xffff, 0xffff, 0xffff
  53 };
  54 static u16 green16[] __read_mostly = {
  55     0x0000, 0x0000, 0xaaaa, 0xaaaa, 0x0000, 0x0000, 0x5555, 0xaaaa,
  56     0x5555, 0x5555, 0xffff, 0xffff, 0x5555, 0x5555, 0xffff, 0xffff
  57 };
  58 static u16 blue16[] __read_mostly = {
  59     0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa,
  60     0x5555, 0xffff, 0x5555, 0xffff, 0x5555, 0xffff, 0x5555, 0xffff
  61 };
  62
  63 static const struct fb_cmap default_2_colors = {
  64     .len=2, .red=red2, .green=green2, .blue=blue2
  65 };
  66 static const struct fb_cmap default_8_colors = {
  67     .len=8, .red=red8, .green=green8, .blue=blue8
  68 };
  69 static const struct fb_cmap default_4_colors = {
  70     .len=4, .red=red4, .green=green4, .blue=blue4
  71 };
  72 static const struct fb_cmap default_16_colors = {
  73     .len=16, .red=red16, .green=green16, .blue=blue16
  74 };
  75
  76
  77
  78 /**
  79  *      fb_alloc_cmap - allocate a colormap
  80  *      @cmap: frame buffer colormap structure
  81  *      @len: length of @cmap
  82  *      @transp: boolean, 1 if there is transparency, 0 otherwise
  83  *      @flags: flags for kmalloc memory allocation
  84  *
  85  *      Allocates memory for a colormap @cmap.  @len is the
  86  *      number of entries in the palette.
  87  *
  88  *      Returns negative errno on error, or zero on success.
  89  *
  90  */
  91
  92 int fb_alloc_cmap_gfp(struct fb_cmap *cmap, int len, int transp, gfp_t flags)
  93 {
  94         int size = len * sizeof(u16);
  95         int ret = -ENOMEM;
  96
  97         flags |= __GFP_NOWARN;
  98
  99         if (cmap->len != len) {
 100                 fb_dealloc_cmap(cmap);
 101                 if (!len)
 102                         return 0;
 103
 104                 cmap->red = kmalloc(size, flags);
 105                 if (!cmap->red)
 106                         goto fail;
 107                 cmap->green = kmalloc(size, flags);
 108                 if (!cmap->green)
 109                         goto fail;
 110                 cmap->blue = kmalloc(size, flags);
 111                 if (!cmap->blue)
 112                         goto fail;
 113                 if (transp) {
 114                         cmap->transp = kmalloc(size, flags);
 115                         if (!cmap->transp)
 116                                 goto fail;
 117                 } else {
 118                         cmap->transp = NULL;
 119                 }
 120         }
 121         cmap->start = 0;
 122         cmap->len = len;
 123         ret = fb_copy_cmap(fb_default_cmap(len), cmap);
 124         if (ret)
 125                 goto fail;
 126         return 0;
 127
 128 fail:
 129         fb_dealloc_cmap(cmap);
 130         return ret;
 131 }
 132
 133 int fb_alloc_cmap(struct fb_cmap *cmap, int len, int transp)
 134 {
 135         return fb_alloc_cmap_gfp(cmap, len, transp, GFP_ATOMIC);
 136 }
 137
 138 /**
 139  *      fb_dealloc_cmap - deallocate a colormap
 140  *      @cmap: frame buffer colormap structure
 141  *
 142  *      Deallocates a colormap that was previously allocated with
 143  *      fb_alloc_cmap().
 144  *
 145  */
 146
 147 void fb_dealloc_cmap(struct fb_cmap *cmap)
 148 {
 149         kfree(cmap->red);
 150         kfree(cmap->green);
 151         kfree(cmap->blue);
 152         kfree(cmap->transp);
 153
 154         cmap->red = cmap->green = cmap->blue = cmap->transp = NULL;
 155         cmap->len = 0;
 156 }
 157
 158 /**
 159  *      fb_copy_cmap - copy a colormap
 160  *      @from: frame buffer colormap structure
 161  *      @to: frame buffer colormap structure
 162  *
 163  *      Copy contents of colormap from @from to @to.
 164  */
 165
 166 int fb_copy_cmap(const struct fb_cmap *from, struct fb_cmap *to)
 167 {
 168         unsigned int tooff = 0, fromoff = 0;
 169         size_t size;
 170
 171         if (to->start > from->start)
 172                 fromoff = to->start - from->start;
 173         else
 174                 tooff = from->start - to->start;
 175         if (fromoff >= from->len || tooff >= to->len)
 176                 return -EINVAL;
 177
 178         size = min_t(size_t, to->len - tooff, from->len - fromoff);
 179         if (size == 0)
 180                 return -EINVAL;
 181         size *= sizeof(u16);
 182
 183         memcpy(to->red+tooff, from->red+fromoff, size);
 184         memcpy(to->green+tooff, from->green+fromoff, size);
 185         memcpy(to->blue+tooff, from->blue+fromoff, size);
 186         if (from->transp && to->transp)
 187                 memcpy(to->transp+tooff, from->transp+fromoff, size);
 188         return 0;
 189 }
 190
 191 int fb_cmap_to_user(const struct fb_cmap *from, struct fb_cmap_user *to)
 192 {
 193         unsigned int tooff = 0, fromoff = 0;
 194         size_t size;
 195
 196         if (to->start > from->start)
 197                 fromoff = to->start - from->start;
 198         else
 199                 tooff = from->start - to->start;
 200         if (fromoff >= from->len || tooff >= to->len)
 201                 return -EINVAL;
 202
 203         size = min_t(size_t, to->len - tooff, from->len - fromoff);
 204         if (size == 0)
 205                 return -EINVAL;
 206         size *= sizeof(u16);
 207
 208         if (copy_to_user(to->red+tooff, from->red+fromoff, size))
 209                 return -EFAULT;
 210         if (copy_to_user(to->green+tooff, from->green+fromoff, size))
 211                 return -EFAULT;
 212         if (copy_to_user(to->blue+tooff, from->blue+fromoff, size))
 213                 return -EFAULT;
 214         if (from->transp && to->transp)
 215                 if (copy_to_user(to->transp+tooff, from->transp+fromoff, size))
 216                         return -EFAULT;
 217         return 0;
 218 }
 219
 220 /**
 221  *      fb_set_cmap - set the colormap
 222  *      @cmap: frame buffer colormap structure
 223  *      @info: frame buffer info structure
 224  *
 225  *      Sets the colormap @cmap for a screen of device @info.
 226  *
 227  *      Returns negative errno on error, or zero on success.
 228  *
 229  */
 230
 231 int fb_set_cmap(struct fb_cmap *cmap, struct fb_info *info)
 232 {
 233         int i, start, rc = 0;
 234         u16 *red, *green, *blue, *transp;
 235         u_int hred, hgreen, hblue, htransp = 0xffff;
 236
 237         red = cmap->red;
 238         green = cmap->green;
 239         blue = cmap->blue;
 240         transp = cmap->transp;
 241         start = cmap->start;
 242
 243         if (start < 0 || (!info->fbops->fb_setcolreg &&
 244                           !info->fbops->fb_setcmap))
 245                 return -EINVAL;
 246         if (info->fbops->fb_setcmap) {
 247                 rc = info->fbops->fb_setcmap(cmap, info);
 248         } else {
 249                 for (i = 0; i < cmap->len; i++) {
 250                         hred = *red++;
 251                         hgreen = *green++;
 252                         hblue = *blue++;
 253                         if (transp)
 254                                 htransp = *transp++;
 255                         if (info->fbops->fb_setcolreg(start++,
 256                                                       hred, hgreen, hblue,
 257                                                       htransp, info))
 258                                 break;
 259                 }
 260         }
 261         if (rc == 0)
 262                 fb_copy_cmap(cmap, &info->cmap);
 263
 264         return rc;
 265 }
 266
 267 int fb_set_user_cmap(struct fb_cmap_user *cmap, struct fb_info *info)
 268 {
 269         int rc, size = cmap->len * sizeof(u16);
 270         struct fb_cmap umap;
 271
 272         if (size < 0 || size < cmap->len)
 273                 return -E2BIG;
 274
 275         memset(&umap, 0, sizeof(struct fb_cmap));
 276         rc = fb_alloc_cmap_gfp(&umap, cmap->len, cmap->transp != NULL,
 277                                 GFP_KERNEL);
 278         if (rc)
 279                 return rc;
 280         if (copy_from_user(umap.red, cmap->red, size) ||
 281             copy_from_user(umap.green, cmap->green, size) ||
 282             copy_from_user(umap.blue, cmap->blue, size) ||
 283             (cmap->transp && copy_from_user(umap.transp, cmap->transp, size))) {
 284                 rc = -EFAULT;
 285                 goto out;
 286         }
 287         umap.start = cmap->start;
 288         lock_fb_info(info);
 289         rc = fb_set_cmap(&umap, info);
 290         unlock_fb_info(info);
 291 out:
 292         fb_dealloc_cmap(&umap);
 293         return rc;
 294 }
 295
 296 /**
 297  *      fb_default_cmap - get default colormap
 298  *      @len: size of palette for a depth
 299  *
 300  *      Gets the default colormap for a specific screen depth.  @len
 301  *      is the size of the palette for a particular screen depth.
 302  *
 303  *      Returns pointer to a frame buffer colormap structure.
 304  *
 305  */
 306
 307 const struct fb_cmap *fb_default_cmap(int len)
 308 {
 309     if (len <= 2)
 310         return &default_2_colors;
 311     if (len <= 4)
 312         return &default_4_colors;
 313     if (len <= 8)
 314         return &default_8_colors;
 315     return &default_16_colors;
 316 }
 317
 318
 319 /**
 320  *      fb_invert_cmaps - invert all defaults colormaps
 321  *
 322  *      Invert all default colormaps.
 323  *
 324  */
 325
 326 void fb_invert_cmaps(void)
 327 {
 328     u_int i;
 329
 330     for (i = 0; i < ARRAY_SIZE(red2); i++) {
 331         red2[i] = ~red2[i];
 332         green2[i] = ~green2[i];
 333         blue2[i] = ~blue2[i];
 334     }
 335     for (i = 0; i < ARRAY_SIZE(red4); i++) {
 336         red4[i] = ~red4[i];
 337         green4[i] = ~green4[i];
 338         blue4[i] = ~blue4[i];
 339     }
 340     for (i = 0; i < ARRAY_SIZE(red8); i++) {
 341         red8[i] = ~red8[i];
 342         green8[i] = ~green8[i];
 343         blue8[i] = ~blue8[i];
 344     }
 345     for (i = 0; i < ARRAY_SIZE(red16); i++) {
 346         red16[i] = ~red16[i];
 347         green16[i] = ~green16[i];
 348         blue16[i] = ~blue16[i];
 349     }
 350 }
 351
 352
 353     /*
 354      *  Visible symbols for modules
 355      */
 356
 357 EXPORT_SYMBOL(fb_alloc_cmap);
 358 EXPORT_SYMBOL(fb_dealloc_cmap);
 359 EXPORT_SYMBOL(fb_copy_cmap);
 360 EXPORT_SYMBOL(fb_set_cmap);
 361 EXPORT_SYMBOL(fb_default_cmap);
 362 EXPORT_SYMBOL(fb_invert_cmaps);